Congrats on the new car. I just got mine this past February. A few visual things that look good is debadge the car, remove the gm fender badges and the chevy emblem on rear as well as cobalt badging and possibly dealer badges if you have them. Paint the front chevy grill emblem. I dont think rims will void the warranty, keep the stock tires though, incase you dont want to take any chances so you can swap em out real quick before it would have to have work performed. If you need any sites to find parts, you can go to ************* and click on the links to alot of sites on the left side of the page. As for exhaust, Im sure some other people will tune in and give some advice on what is good.